// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
 *******************************************************************************
 * Copyright (C) 2012-2014, International Business Machines
 * Corporation and others.  All Rights Reserved.
 *******************************************************************************
 * CollationRoot.java, ported from collationroot.h/.cpp
 *
 * C++ version created on: 2012dec17
 * created by: Markus W. Scherer
 */

package com.ibm.icu.impl.coll;

import com.ibm.icu.impl.ICUBinary;
import com.ibm.icu.impl.ICUData;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.MissingResourceException;

/** Collation root provider. */
public final class CollationRoot { // purely static
    private static final CollationTailoring rootSingleton;
    private static final RuntimeException exception;

    public static final CollationTailoring getRoot() {
        if (exception != null) {
            throw exception;
        }
        return rootSingleton;
    }

    public static final CollationData getData() {
        CollationTailoring root = getRoot();
        return root.data;
    }

    static final CollationSettings getSettings() {
        CollationTailoring root = getRoot();
        return root.settings.readOnly();
    }

    static { // Corresponds to C++ load() function.
        CollationTailoring t = null;
        RuntimeException e2 = null;
        try {
            ByteBuffer bytes = ICUBinary.getRequiredData("coll/ucadata.icu");
            CollationTailoring t2 = new CollationTailoring(null);
            CollationDataReader.read(null, bytes, t2);
            // Keep t=null until after the root data has been read completely.
            // Otherwise we would set a non-null root object if the data reader throws an exception.
            t = t2;
        } catch (IOException e) {
            e2 =
                    new MissingResourceException(
                            "IOException while reading CLDR root data",
                            "CollationRoot",
                            ICUData.ICU_BUNDLE + "/coll/ucadata.icu");
        } catch (RuntimeException e) {
            e2 = e;
        }
        rootSingleton = t;
        exception = e2;
    }
}
